I assume you are talking about slick shearing. We like to shear all of our steers about a month to a month and a half from the show, then do it again a couples days before. For us this seems to work better so that we can have time to really condition the skin and the little bit of hair that is left pops more instead of having a stale look.
I'm sure there is no right or wrong but like i said, this seems to work for us.
eric